Are DNA and Blood Tests Accepted by Bais Din?

The Impact of Technology on Evidence – Part I Based on a shiur given by Rabbi Yaakov Rappaport

The Mishnah in Sanhedrin Daf 24B discusses many different types of people who are posel l’eidus, disqualified to bear testimony, for example, sochrei shviis, those who do business with the produce of Eretz Yisroel during the seventh year of the shmita cycle . Since these are people that do aveirosbecause of financial gain they are subject to a chashash of sheker. We suspect that they may be lying for financial gain and therefore we do not accept their testimony.

It is interesting that in the twentieth century, there are new ways of accepting testimonies in secular courts. For example, blood tests are accepted to determine parental identity and many other things as well. Not only do we have blood tests nowadays, we also have polygraph tests to see if someone is lying. We also have DNA. All of these three tests, blood tests, polygraph and DNA have been discussed in Rabbinical literature as to whether they are acceptable in Bais Din or not.

I would like to discuss some of the main Teshuvos which have been written pertaining to blood tests and DNA.

In the 1950’s, it was first discovered how to make blood tests that could define parental identity. Subsequently, a famous Teshuva was written on this subject by Rav Bentzion Chai Uziel, the chief Sephardic Rabbi in Eretz Yisroel and published in his sefer Shaari Uziel. He writes that blood tests are not acceptable for parental identity. He quotes a fascinating Gemara in Niddah 30A. The Gemara states, there are three partners in creation of a person: Hashem, his mother and his father. The Gemara wonders as to how they all contribute to the child? Concerning the mother the Gemara responds that she gives the red material for the blood. The Gemora goes on to say that the father gives the material for the bones. Says Rav Uziel, since it is the mother who gives the blood, how can the father at all be proven to be the father through the blood test?

A fascinating counter-argument is found in the Mishnas Avraham, Even Haezer, Daled s.k. Alef, by Rav Shlomo Zalman Aurbach who counters R’ Uziel and tries to say that blood tests should be permitted in Bais Din. He offers the following logic: Granted, the Gemara says that the mother gives the blood for the child but, it doesn’t mean that it is all, 100%, the mother’s. Rather, the mother provides the catalyst for the production of the blood thereby, leaving open the possibility of paternal influence on the blood as well, even according to Chazal. Therefore, according to Rav Shlomo Zalman while it is true that the mother starts the production of the blood, but it’s not 100% only of the mother. The father’s influence is also seen in the blood.

Also, Rav Kook, in Daas Cohen, Kuf nun quotes an interesting halacha. The halacha is in Orach Chaim, that if a doctor says on Yom Kippur that a sick patient cannot fast at all because it’s dangerous for him to fast and the person says, “I’m fine, I want to fast, I don’t need to eat.” The halacha is that we feed him. We force him to listen to the doctor and he has to eat. In the opposite situation, when the doctor says that it’s easy for him to fast, and there’s no harm in him fasting at all, and he says, “No, it will harm me”, the halacha is that he also eats and does not fast. Meaning, we listen to him when he contradicts the doctor, when he says, “I must eat.” We listen to the doctor when he contradicts the patient, when the doctor says, “He needs to eat.”

So what do we see from this? Do we listen to the doctor, or do we listen to the patient? R’ Kook says, that actually, it’s a sofek. Scientific knowledge in halacha is treated as a sofek. Since it’s treated as a sofek, therefore, we’re machmir in pikuach nefesh and we use the doctor to say if the patient needs to eat. But if the doctor says, he could fast, and the patient says he needs to eat, we listen to the patient, because science only creates a sofek. From this Halacha we see that science is not treated by Halacha as being 100% conclusive. It merely makes a sofek. Therefore, parental identity also can’t be proven conclusively through scientific blood tests.

And so, it was accepted by Rav Waldenburg, in his Teshuvos Tzitz Eliezer siman tes vav. The Tzitz Eliezer also says there that, in the Bais Din of the Rabbanut in Eretz Yisroel, they cannot at all accept the proof of blood tests. That is the accepted decision, that blood tests are not accepted at all, in any Bais Din. However, R’ Herzog in an article published in Uhsia, Lamed Hey, says there, that blood tests are acceptable. Even though he was the Chief Rabbi, the Batei Din in Eretz Yisroel did not accept blood tests.

There is a famous story concerning Rav Saadya Gaon that is brought in the Sefer Chassidim and the Levush. The Sefer Chassidim can be found inSiman Reish Lamed Beis. Rav Sadya Gaon once had a shayla come in front of him concerning a slave, his owner and the owner’s child. The slave’s owner, died. The slave came into Bais Din and said, “I’m not the deceased owner’s slave. I’m his son. This other person, he’s his slave”. To which the real son countered, “No. I’m the son and he’s the slave.” So there’s a machlokes, who’s the slave, and who’s the real son? The nafka mina is, who inherits the person who was niftar, the father? Rav Sadya Gaon didn’t know how to rule. Rav Sadya Gaon did a very interesting blood test. He had the corpse dug up, and the bones of the corpse placed in a jar. After he placed the bones of the corpse in a jar, he took blood samples from both people who claimed to be his son, and put the blood on the bones of the corpse. The bones of the corpse absorbed the blood of the real son. The bones of the corpse did not absorb the blood of the slave. So Rav Sadya Gaon ruled, that the blood of the person who the bones absorbed, that is the true son.

Based on this story and psak many poskim say, that we see that Rav Sadya Gaon used this as a new proof and so too, nowadays, we should also consider blood tests a good proof as to who the father is.

However, this is rejected by many piskei Rabbanim in Eretz Yisroel by the following logic. There is a fascinating Gemara in Kiddushin 71 and a teshuva of Rav Elyashiv in Kovetz Teshuvos Lamed Hey based on this Gemara. The Gemara tells us that a person should not look out to reveal mamzerim. Since the halacha is that a person should not look out to reveal mamzerim, we try not to do any tests that will show that a person is a mamzer. Therefore, even though a father’s identity could be relied upon perhaps, through blood tests, we will not do blood tests, because that could show, chas v’sholom, there’s a mamzer, and we do not look out to reveal mamzerim. True there will be a nafka mina in money, but it will also be a proof that he’s a mamzer and we do not want, Chas V’sholom, to prove anyone to be a mamzer.

Thus far we have discussed the halachos of blood tests. What is the halacho concerning DNA? Rav Ovadiah Yosef, in a Teshuva discusses a case that came before him and R’ Kulik in the Yerushalmi Beis Din, concerning a young man and a woman who lived together without the benefit of marriage. Sometime after the couple separated, the woman was discovered to be pregnant and she subsequently gave birth to a child. The young man claimed to be the child’s father, while the young woman vigorously denied this claim. The man demanded that the DNA test be administered to prove the validity of his claim, and the woman refused to consent. A Bais Din cautioned that if the woman persisted in the refusal to take the DNA sample from her child for the DNA test it would be interpreted as an admission that the young man is indeed the father.

Rav Ovadiah Yosef said that we cannot threaten anyone with DNA, because DNA is the same thing as a blood test. And therefore, it cannot be accepted in Bais Din based on the previous logic we said from Rav Kook that science is not considered to be 100% conclusive. It merely creates asofek. DNA therefore is not accepted in Bais Din.